There has widely been used an image forming apparatus, such as a copying machine, a facsimile, and a printer, that uses an electrophotographic system to form an electrostatic latent image on a photoconductive member, develop the electrostatic latent image using a toner which is a developer, and transfer an obtained toner image onto a transfer sheet. In order to enable continuous image forming operation, the image forming apparatus of this type has a mechanism in which a toner is supplied to a developing section in such a manner as to prevent the developing section to run out of the toner.
As a method that supplies a toner to the developing section of an image forming apparatus, there is known the method in which a toner supply container containing a toner in the main body thereof is provided in the image forming apparatus, and the container main body is rotated to convey the toner outside through a toner supply port of the container main body.
The toner supply container disclosed in Patent Literature 1 is constituted by a cylindrical container body containing a toner therein and a toner discharge unit having a toner discharge port for discharging the toner contained in the container main body outside the toner supply container. An opening having a diameter smaller than the diameter of the container main body is formed in one end surface of the container main body, and the container main body and toner discharge unit are engaged with each other at an engagement portion in a state where the edge of the opening and a seal member provided in a seal member installation portion in the toner discharge unit contact each other. The container body has a spiral groove on the inner peripheral surface thereof. When the toner supply container is attached to the image forming apparatus substantially horizontally, and the container main body is rotated in a predetermined direction about the axis line thereof in a frictional sliding manner with respect to the seal member, the toner contained in the container main body is sequentially migrated toward the opening side by means of the spiral groove to be fed into the opening. The toner that has reached the opening is pushed out from the opening into the toner discharge unit and then discharged outside through the toner discharge port of the toner discharge unit.
When the toner in the container main body is consumed and used up after the repetition of an image forming process, the empty toner supply container is removed from the image forming apparatus, and another toner supply container having a container main body filled with a toner is attached to the image forming apparatus. In terms of effective use of resources, the removed toner supply container is preferably reused.
In the case where the toner supply container is reused, the seal member, which is deteriorated or deformed with age, is preferably replaced with new one so as to ensure sealing performance. However, in the existing toner supply container, the seal member is brought into close contact with the seal member installation surface of the seal member installation portion or inner wall of the toner supply container, making it difficult to pinch the seal member when the seal member is removed from the seal member installation surface. Thus, it takes time and effort to remove the seal member from the seal member installation surface.
In order to make it easier to remove the seal member from the seal member installation portion, a method can be considered in which a portion around the seal member installation portion is constituted by a plurality of parts so as to be disassembled. However, the number of parts is increased to increase the cost of the toner supply container.    [Patent Literature 1] Japanese Patent (JP-B) No. 3628539